Growth pattern and age at menarche of obese girls in a transitional society.

Childhood obesity is an increasing problem in a transitional society such as Thailand. To study physical growth and puberty in obese children, a cross-sectional survey of growth and age at menarche was carried out in schoolgirls aged between 8 and 16 years old. The 3,120 girls were divided into two groups based on weight-for-height criteria. Girls with weight-for-height between 80 and 120% were classified as normal stature (2,625; 84.1%) and those more than 120% were obese (495; 15.9%). Using probit analysis, age at menarche in obese girls was 0.9 year earlier than normal stature girls (11.5 years vs 12.4 years). At age 12, obese girls were reaching menarche 2.8 times more when compared with the normal stature girls. In terms of growth pattern, obese girls were taller and grew faster during the prepubertal period, and then reached their final height earlier than the normal stature girls (13 years vs 15 years). The final height in obese girls was significantly shorter (153.0 cm and 155.0 cm, p = 0.01). We conclude that: 1) obese girls grow faster, have earlier menarche and then stop growing earlier, and 2) obese girls tend to be shorter as adults, compared with normal stature girls.